Draft control



t f -9 T. A. GERLACH 1,974,567

DRAFT CONTROL Filed Nov. 20. 1931 Patented Sept. 25, 1934 UNITED STATES PATENT OFFICE- 1,974,567 DRAFT CONTROL Thomas A. Gerlach, Harvey, Ill. Application November 20, 1931, Serial No. 576,239 11 Claims. (01. 236-45) My invention relates to draft regulators and more particularly to a combination draft regulator and check draft.

The object of my invention isto make a simple and inexpensive device which will automatically provide a uniform predetermined draft in a furnace or stove regardless of the condition of the Weather outside. 7 r

- In addition, it is also the purpose of this invention to provide a device of this character which willserve in the place commonly used for check dampers for furnaces and will be more efficient than such dampers in that the amount of checking applied is automatically dependent on the condition of the weather and the amount of fire in the furnace, closing as the fire goes down and opening as the fire comes up. The device is also arranged so that it may be regulated manu ally when the weather or the amount of fire in the furnace will not affect its action.

Another particular purpose of the invention is to; provide a device of this character wherein automatic draft regulation is obtained by means of a floating disk and a guide member without the addition of a weight or lever of any kind.

I will describe the preferred form. of my invention byreferenceto the accompanying drawing wherein- Fig. l is a longitudinal section through the draft regulator illustrating the manner in which it operates when attached to the furnace;

Fig. 2 illustrates, the positioning of the regulator to adjust it for variations in furnace or weather conditions; i.

Fig. 3 illustrates the extreme position of the regulator in which it no longer functions as a stabilizer. i

Referring now in detail to the drawing, the numeral 5 indicates an inlet pipe which leads to the furnace stack stove pipe or other outlet con-. duit for furnace gases. The numeralfi refers to a casing which, as shown, has an outlet opening at 7 into the connecting pipe 5 which is usually very short and which may be a part of the furnace chimney or flue. Thelcasinghasat the bottom thereof. a round opening 8 through which the air may enter, and, after passing upwardly through the baffle member 9, the air may pass through'the outlet 7 to the chimney.

It is well known that as the fire temperature increases there is a tendency for a higher speed of gas and a lower pressure of gas in the outlet conduit or chimney. Moreover, sudden gusts of wind or high wind storm conditions may change the atmospheric pressure around the furnace so that it is diificult to maintain a proper relation between the air pressure at the outlet of the furnace and the air pressure around the furnace which is the same as that at the inlet. I

The battle member 9 as shown is an annular cone shaped member increasing in diameter toward the top, and centrally disposedwith respect to this member is a guide rod 10. This guide rod 10 serves to guide a floating disk 11' which is free to move up and down on theguide rod from the lowermost position shown in dotted lines in Fig. 1 to any height up to the top of the easing. -This disk being free to rise as the pressure increases on the lower surface thereof will during thenormal operation of the furnace rise and fall in response to changes in difference in pressure between the chimney and the atmosphere. As it rises, the disk 11 allows more air to enter the chimney and thus reduces the draft so as to compensate for the excess pressure which caused it to rise. 1

Thus I have provided a very simple regulating device which is fully automatic in its operation and does not require the use of any weights or levers of any sort.

The guide rod is held at the bottom by a cross bar shown at 12. Thisrod is also screw-threaded to receive the lock nut. 13 and to receive the control disk 14 which may be moved up or down relative to the opening at 8 so as to vary the total amount of air that may enter through the open,- ing 8. The disk 14 is preferably itself screwthreaded onto rod 10, and nut 15 is merely a lock nut which can be jammed against it to prevent its, being, turned accidentally and thus being thrown out of adjustment. i

The cone-shaped member 9 in addition to acting as a regulator on the amount of air it admitted to the chimney also acts as a baflie to prevent soot and dust from the chimney as well as the excessive: heat from impairingthe free work ing of the damper 11 on the guide rod. 1

It will be noted that the casing 6 is swivelly mounted upon the member 5. by means of the sleeve 16 and flanges 17, 18, and 19 so that this so much resistance to changes in pressure on the opposite sides thereof. More specifically, when the casing is in the position shown in Fig. 2, the disk will move upwardly for a less difference in pressure than it will in the position shown in Fig. 1. In this way, the draft regulator may be adjusted to the proper draft for different chimneys or for the same chimney at different times.

When the guide rod is in the horizontal position shown in Fig. 3 or nearly so, the damper opens widely, and the device then acts as a check draft. When the device is used as a draft stabilizer only, the control chain 20 and the counter weight 21 are omitted entirely, and the floating disk 11 bobs up and down due to the change in velocity of wind or other causes so that the draft of the furnace remains almost uniform. The

lower disk 14 can be moved up or down to accommodate the total air float for different furnaces, and, then by tilting the casing, it may be adjusted for any desired draft of the furnace.

From the above description, it is believed that the construction and advantages of this device will be clear to those skilled in this art and the advantages thereof readily apparent.

Having thus described one specific form of my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a draft regulator, a casing for attachment to the furnace outlet conduit or stack, said casing opening into said conduit and also having a downwardly directed opening to atmosphere, a floating disk in said casing movable toward and away from said opening, and a rigid guide means for guiding said disk toward and away from said opening, said casing having therein an annular baflle rising about said opening, said baflle permitting more air to enter as the disk rises.

2. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a bailie surrounding said opening and projecting up into said casing whereby to retard the backflow of ashes and gas to said opening, and a draft regulating disk within said bafiie.

3'. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a baffle surrounding said opening and projecting up into said casing whereby to retardthe backfiow of ashes and gas to said opening, and a draft regulating disk within said baffle, said casing having a guide rod for said-disk.

4. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a bafile surrounding said opening and projecting up into said casing whereby to retard the backflow of ashes and gas to said opening, and a draft regulating-disk Within said baffle, said casing having a guide rod for said disk, and said rod running down through said opening and being provided below said opening with means for regulating the amount of air inflow through said opening.

5. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a baffle surrounding said opening and projecting up into said casing whereby to retard the backflow of ashes and gas to said opening, and a draft regulating disk within said baflle, said casing having a guide rod for said disk, said casing being movable to tilt said rod relative to the vertical.

6. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a baffle surrounding said opening and projecting up into said casing whereby to retard the backfiow of ashes and gas to said opening, and a draft regulating disk within said baffle, said baffle expanding in circumference above said opening.

7. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a baffle surrounding said opening and projecting up into said casing whereby to retard the backflow of ashes and 'gas to said opening, and a draft regulating disk within said bafile, said baffle gradually expanding outwardly from said opening to its upper edge.

8. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a baflie surrounding said opening and projecting up into said casing whereby to retard the backflow of ashes and gas to said opening, and a draft regulating disk within said baffle, said baffle extending substantially to the top of the opening to the furnace.

9. In a furnace draft regulator, a casing having an opening into the furnace outlet conduit, and having a bottom opening, a battle surrounding said opening and projecting up into said casing whereby to retard the backfiow of ashes and gas to said opening, and a draft regulating disk within said bafile, said casing having a guide rod for said disk, said casing being pivotally mounted whereby said guide rod may be moved between horizontal and vertical position.

10. A draft regulator for furnaces comprising means providing an air inlet to the furnace outlet, a casing covering said inlet and rotatable on said means, said casing having an air inlet at substantially right angles to its axis of rotation, said casing also having a disk therein overlying said inlet and movable bodily toward and away from said inlet in response to fluctuations in draft, guide means in the casing for guiding said disk in its movement toward and away from the inlet, rotation of said casing upon its axis operating to vary the direction of movement of the'disk with respect to the horizontal.

11. A draft regulator for furnaces comprising means providing an air inlet to the furnace outlet, a casing covering said inlet and rotatable on said means, said casing having an air inlet at substantially right angles to its axis of rotation. said casing also having a disk therein overlying said inlet and movable bodily toward and away from said inlet in response to fluctuations in draft, guide means in the casing for guiding said disk in its movement toward and away from the inlet, rotation of said casing upon its axis operating to vary the direction of movement of the disk with respect to the horizontal, said casing having means for varying the flow of air into the casing through its inlet for any position of the disk.

THOMAS A. GERLACH. 

